High-resolution x-ray crystallography has had unparalleled impact on the course of biological and biomedical research. Structural information is providing exquisite detail about the assembly and control of macromolecular complexes and the mechanisms of macromolecular function. Future advances in biological and biomedical science require an ever-expanding structural data base to keep pace with the rapidly growing body of biochemical and genetic data. Given the unprecedented volume of data accruing from the genome sequencing projects, there is no period in history that will benefit as much from an expansion of structural resources and methodologies. This project is directly taking up this challenge by expanding the national and worldwide MAD data collection facilities and in developing new technologies for efficient and rapid de novo structure solution by MAD crystallography.